Neutron capture therapy system

ABSTRACT

A neutron capture therapy system includes an accelerator for accelerating charged particles to generate a charged particle beam, a beam transmitting device, and a neutron beam generating device. The neutron beam generating device further includes a first, a second and a third neutron beam generating device. The beam transmitting device further includes a first transmitting device connected to the accelerator, a beam direction conversion device configured to switch a traveling direction of the charged particle beam, and a second, a third and a fourth transmitting device that respectively transmit the charged particle beam from the beam direction conversion device to the first, the second and the third neutron beam generating device, wherein two of the first, the third and the fourth transmitting device define a first plane, a first and a second transmitting device define a second plane, and the first plane is different from the second plane.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This application is a continuation application of InternationalApplication No. PCT/CN2018/100753, filed on Aug. 16, 2018, which claimspriority to Chinese Patent Application No. 201710799364.4, filed on Sep.7, 2017; Chinese Patent Application No. 201710800745.X, filed on Sep. 7,2017; Chinese Patent Application No. 201710800921.X, filed on Sep. 7,2017; and Chinese Patent Application No. 201710799911.9, filed on Sep.7, 2017, the disclosures of which are hereby incorporated by reference.

FIELD

The present disclosure relates to a radiation irradiation system, and inparticular to a neutron capture therapy system.

BACKGROUND

The background description provided herein is for the purpose ofgenerally presenting the context of the disclosure. Work of thepresently named inventors, to the extent it is described in thisbackground section, as well as aspects of the description that may nototherwise qualify as prior art at the time of filing, are neitherexpressly nor impliedly admitted as prior art against the presentdisclosure.

As atomics moves ahead, such radiotherapy as Cobalt-60, linearaccelerators and electron beams has been one of major means to cancertherapy. However, conventional photon or electron therapy has beenundergone physical restrictions of radioactive rays; for example, manynormal tissues on a beam path will be damaged as tumor cells aredestroyed. On the other hand, sensitivity of tumor cells to theradioactive rays differs greatly, so in most cases, conventionalradiotherapy falls short of treatment effectiveness on radioresistantmalignant tumors (such as glioblastoma multiforme and melanoma).

For the purpose of reducing radiation damage to the normal tissuesurrounding a tumor site, target therapy in chemotherapy has beenemployed in the radiotherapy. While for high-radioresistant tumor cells,radiation sources with high RBE (relative biological effectiveness)including such as proton, heavy particle and neutron capture therapyhave also developed. Among them, the neutron capture therapy combinesthe target therapy with the RBE, such as the boron neutron capturetherapy (BNCT). By virtue of specific grouping of boronatedpharmaceuticals in the tumor cells and precise neutron beam regulation,BNCT is provided as a better cancer therapy choice than conventionalradiotherapy.

Various radiations are generated during radiotherapy. For example,neutrons and photons of low-energy to high-energy are generated duringboron neutron capture therapy. These radiations may cause differentdegrees of damage to normal human tissues. Therefore, in the field ofradiotherapy, how to reduce radiation pollution to the externalenvironment, medical staff or normal tissues of patients is an extremelyimportant issue while effective treatment is achieved. Moreover, atpresent, in accelerator-based BNCT, a plurality of patients cannot betreated simultaneously, or a plurality of irradiation rooms are notappropriately arranged, resulting in a relatively long transmission pathof a charged particle beam to cause a loss.

Therefore, it is necessary to propose a new technical solution toresolve the foregoing problem.

SUMMARY

To resolve the foregoing problem, an aspect of the present disclosureprovides a neutron capture therapy system, including an accelerator, abeam transmitting device, and a neutron beam generating device, whereinthe accelerator is configured to accelerate charged particles togenerate a charged particle beam, the beam transmitting device isconfigured to transmit the charged particle beam generated by theaccelerator to the neutron beam generating device, and the neutron beamgenerating device is configured to generate a therapeutic neutron beam.The neutron beam generating device further includes a first neutron beamgenerating device, a second neutron beam generating device, and a thirdneutron beam generating device. The beam transmitting device furtherincludes a first transmitting device connected to the accelerator, abeam direction conversion device configured to switch a travelingdirection of the charged particle beam, and a second transmittingdevice, a third transmitting device, and a fourth transmitting devicethat respectively transmit the charged particle beam from the beamdirection conversion device to the first neutron beam generating device,the second neutron beam generating device, and the third neutron beamgenerating device, wherein two of the first transmitting device, thethird transmitting device, and the fourth transmitting device define afirst plane, the first transmitting device and the second transmittingdevice define a second plane, and the first plane is different from thesecond plane. In such an arrangement manner, space may be effectivelyutilized, a plurality of patients may be simultaneously treated, and abeam transmission path may not be excessively extended to ensure a smallloss.

Implementations of this aspect may include one or more of the followingfeatures.

More particularly, the first transmitting device transmits the chargedparticle beam in an X-axis direction, and transmission directions of thethird transmitting device and the fourth transmitting device are on anXY plane and form an angle greater than 0 degrees. Furthermore, thesecond transmitting device transmits the charged particle beam in aZ-axis direction, and the transmission directions of the thirdtransmitting device and the fourth transmitting device and atransmission direction of the first transmitting device form a “Y”shape.

More particularly, the neutron capture therapy system further includes atreatment table, the neutron beam generating device includes a target, abeam shaping assembly, and a collimator, the target is disposed betweenthe beam transmitting device and the beam shaping assembly, the chargedparticle beam generated by the accelerator is irradiated to the targetthrough the beam transmitting device and interacts with the target togenerate neutrons, and the generated neutrons sequentially pass throughthe beam shaping assembly and the collimator to form the therapeuticneutron beam to be irradiated to a patient on the treatment table.

Further, the beam shaping assembly includes a reflector, a moderator, athermal neutron absorber, a radiation shield, and a beam exit, themoderator slows down the neutrons generated from the target to anepithermal neutron energy range, the reflector surrounds the moderatorand guides deflected neutrons back to the moderator to increase theintensity of an epithermal neutron beam, the thermal neutron absorber isconfigured to absorb thermal neutrons to avoid overdosing in superficialnormal tissue during treatment, the radiation shield is disposed at therear of the reflector surrounding the beam exit, and is configured toshield against leaked neutrons and photons to reduce a dose to normaltissue in a non-irradiation area, the collimator is disposed at the rearof the beam exit to converge the neutron beam, a radiation shieldingdevice is disposed between the patient and the beam exit to shieldnormal tissue of the patient from the radiation of beams from the beamexit. The beam transmitting device has a vacuum tube configured toaccelerate or transmit the charged particle beam, the vacuum tubeprotrudes into the beam shaping assembly in the direction of the chargedparticle beam and sequentially passes through the reflector and themoderator, and the target is disposed in the moderator and is located atan end of the vacuum tube.

Further, the neutron capture therapy system further includes anirradiation room, the patient on the treatment table receives treatmentof neutron beam irradiation in the irradiation room, the irradiationroom includes a first irradiation room, a second irradiation room, and athird irradiation room that respectively correspond to the first neutronbeam generating device, the second neutron beam generating device, andthe third neutron beam generating device, and the first irradiationroom, the second irradiation room, and the third irradiation room arerespectively disposed in transmission directions of the secondtransmitting device, the third transmitting device, and the fourthtransmitting device.

Furthermore, the neutron capture therapy system further includes acharged particle beam generation room, the charged particle beamgeneration room accommodates the accelerator and at least part of thebeam transmitting device. The charged particle beam generation roomincludes an accelerator room and a beam transmission room, the firsttransmitting device extends from the accelerator room to the beamtransmission room, at least part of the second neutron beam generatingdevice and at least part of the third neutron beam generating device arerespectively buried in partition walls that respectively separate thesecond irradiation room and the third irradiation room from the beamtransmission room, the third transmitting device and the fourthtransmitting device respectively extend from the beam transmission roomto the second neutron beam generating device and the third neutron beamgenerating device, the first neutron beam generating device is locatedin the first irradiation room, the second transmitting device extendsfrom the beam transmission room to the first irradiation room throughthe floor, and the neutron capture therapy system further includes apreparation room and a control room.

More particularly, the first neutron beam generating device, the secondneutron beam generating device, and the third neutron beam generatingdevice are respectively disposed along transmission directions of thesecond transmitting device, the third transmitting device, and thefourth transmitting device, directions of neutron beams generated by thefirst neutron beam generating device, the second neutron beam generatingdevice, and the third neutron beam generating device are respectivelythe same as the transmission directions of the second transmittingdevice, the third transmitting device, and the fourth transmittingdevice, so that the directions of the neutron beams generated by thesecond neutron beam generating device and the third neutron beamgenerating device are on a same plane, and the direction of the neutronbeam generated by the first neutron beam generating device issubstantially perpendicular to the plane.

More particularly, the beam direction conversion device includes a firstbeam direction conversion assembly and a second beam directionconversion assembly, the beam transmitting device further includes afifth transmitting device that connects the first beam directionconversion assembly and the second beam direction conversion assembly,the second transmitting device connects the first beam directionconversion assembly and the first neutron beam generating device, thethird transmitting device connects the second beam direction conversionassembly and the second neutron beam generating device, and the fourthtransmitting device connects the second beam direction conversionassembly and the third neutron beam generating device.

Further, each of the first beam direction conversion assembly and thesecond beam direction conversion assembly includes a deflectionelectromagnet for deflecting the charged particle beam and a switchelectromagnet for controlling the traveling direction of the chargedparticle beam, the neutron capture therapy system further includes abeam dump configured to check an output of the charged particle beambefore treatment, the first beam direction conversion assembly or thesecond beam direction conversion assembly guides the charged particlebeam to the beam dump, each of the first transmitting device, the secondtransmitting device, the third transmitting device, the fourthtransmitting device, and the fifth transmitting device includes a beamadjuster for the charged particle beam, and each of the secondtransmitting device, the third transmitting device, and the fourthtransmitting device includes a current monitor and a charged particlebeam scanner.

Another aspect of the present disclosure provides a neutron capturetherapy system, including an accelerator, a beam transmitting device,and a first neutron beam generating device, where the accelerator isconfigured to accelerate charged particles to generate a chargedparticle beam, the beam transmitting device is configured to transmitthe charged particle beam generated by the accelerator to the firstneutron beam generating device, the first neutron beam generating deviceis configured to generate a therapeutic neutron beam, and a firstshielding wall is disposed between the first neutron beam generatingdevice and the accelerator to protect an operator from irradiation byneutrons and other radioactive rays leaked from the first neutron beamgenerating device during repair and maintenance of the accelerator andreduce reactions in which the accelerator is activated.

Implementations of this aspect may include one or more of the followingfeatures.

More particularly, the neutron capture therapy system further includes atreatment table, the first neutron beam generating device includes atarget, a beam shaping assembly, and a collimator, the target isdisposed between the beam transmitting device and the beam shapingassembly, the charged particle beam generated by the accelerator isirradiated to the target through the beam transmitting device andinteracts with the target to generate neutrons, and the generatedneutrons sequentially pass through the beam shaping assembly and thecollimator to form the therapeutic neutron beam to be irradiated to apatient on the treatment table.

Further, the beam shaping assembly includes a reflector, a moderator, athermal neutron absorber, a radiation shield, and a beam exit, themoderator slows down the neutrons generated from the target to anepithermal neutron energy range, the reflector surrounds the moderatorand guides deflected neutrons back to the moderator to increase theintensity of an epithermal neutron beam, the thermal neutron absorber isconfigured to absorb thermal neutrons to avoid overdosing in superficialnormal tissue during treatment, the radiation shield is disposed at therear of the reflector surrounding the beam exit, and is configured toshield against leaked neutrons and photons to reduce a dose to normaltissue in a non-irradiation area, the collimator is disposed at the rearof the beam exit to converge the neutron beam, and a radiation shieldingdevice is disposed between the patient and the beam exit to shieldnormal tissue of the patient from the radiation of beams from the beamexit.

Furthermore, the beam transmitting device has a vacuum tube configuredto accelerate or transmit the charged particle beam, the vacuum tubeprotrudes into the beam shaping assembly in the direction of the chargedparticle beam and sequentially passes through the reflector and themoderator, and the target is disposed in the moderator and is located atan end of the vacuum tube.

More particularly, the neutron capture therapy system further includes acharged particle beam generation room and a first irradiation room, thecharged particle beam generation room accommodates the accelerator andat least part of the beam transmitting device, a patient receivestreatment of neutron beam irradiation in the first irradiation room, atleast part of the first neutron beam generating device is buried in afirst partition wall that separates the first irradiation room from thecharged particle beam generation room, and the first shielding wall isdisposed in the charged particle beam generation room.

Further, the charged particle beam generation room includes anaccelerator room and a beam transmission room, the beam transmittingdevice includes a first transmitting device that is connected to theaccelerator and extends from the accelerator room to the beamtransmission room and a second transmitting device that extends from thebeam transmission room to the first neutron beam generating device andtransmits the charged particle beam to the first neutron beam generatingdevice, the first partition wall is a partition wall that separates thefirst irradiation room from the beam transmission room, the firstshielding wall is a partition wall between the accelerator room and thebeam transmission room, and the first transmitting device passes throughthe first shielding wall.

Furthermore, the first transmitting device includes a first beamdirection conversion assembly and a second beam direction conversionassembly configured to switch a traveling direction of the chargedparticle beam, a third transmitting device that connects the acceleratorand the first beam direction conversion assembly, a fourth transmittingdevice that connects the first beam direction conversion assembly andthe second beam direction conversion assembly, and a fifth transmittingdevice that connects the second transmitting device and the second beamdirection conversion assembly, the first shielding wall is disposedbetween the accelerator and the first beam direction conversionassembly, and the third transmitting device passes through the firstshielding wall; or the first shielding wall is disposed between thesecond beam direction conversion assembly and the first neutron beamgenerating device, and the fifth transmitting device passes through thefirst shielding wall; or the first shielding wall is disposed betweenthe first beam direction conversion assembly and the second beamdirection conversion assembly, and the fourth transmitting device passesthrough the first shielding wall. The neutron capture therapy systemfurther includes a second neutron beam generating device and a secondirradiation room, at least part of the second neutron beam generatingdevice is buried in a second partition wall that separates the secondirradiation room from the beam transmission room, the beam transmittingdevice further includes a sixth transmitting device that extends fromthe beam transmission room to the second neutron beam generating deviceand transmits the charged particle beam to the second neutron beamgenerating device, the first transmitting device further includes aseventh transmitting device that connects the sixth transmitting deviceand the second beam direction conversion assembly, when the firstshielding wall is disposed between the second beam direction conversionassembly and the first neutron beam generating device, the seventhtransmitting device also passes through the first shielding wall, eachof the first beam direction conversion assembly and the second beamdirection conversion assembly includes a deflection electromagnet fordeflecting the charged particle beam and a switch electromagnet forcontrolling the traveling direction of the charged particle beam, theneutron capture therapy system further includes a beam dump configuredto check an output of the charged particle beam before treatment, thefirst beam direction conversion assembly or the second beam directionconversion assembly guides the charged particle beam to the beam dump,each of the first transmitting device, the second transmitting device,and the sixth transmitting device includes a beam adjuster for thecharged particle beam, and each of the second transmitting device andthe sixth transmitting device includes a current monitor and a chargedparticle beam scanner.

Further, a second shielding wall is disposed between the first partitionwall and the first shielding wall.

More particularly, a shielding door is disposed in the first shieldingwall, and the shielding door includes a primary shielding door and asecondary shielding door or only includes a primary shielding door orsecondary shielding door.

The third aspect of the present disclosure provides a neutron capturetherapy system, including an accelerator, a beam transmitting device,and a first neutron beam generating device, the accelerator isconfigured to accelerate charged particles to generate a chargedparticle beam, the beam transmitting device is configured to transmitthe charged particle beam generated by the accelerator to the firstneutron beam generating device, the first neutron beam generating deviceis configured to generate a therapeutic neutron beam, the neutroncapture therapy system further includes a charged particle beamgeneration room and a first irradiation room, the charged particle beamgeneration room is configured to accommodate the accelerator and atleast part of the beam transmitting device, a patient receives treatmentof neutron beam irradiation in the first irradiation room, at least partof the first neutron beam generating device is buried in a firstpartition wall that separates the first irradiation room from thecharged particle beam generation room, a first shielding assembly isdisposed at a position where the first neutron beam generating devicepasses on a side, facing the upstream of a beam transmission direction,of the first partition wall. The first shielding assembly is disposed,so that neutrons that overflow or are reflected from the first neutronbeam generating device may be prevented from entering the chargedparticle beam generation room.

Implementations of this aspect may include one or more of the followingfeatures.

More particularly, the neutron capture therapy system further includes atreatment table, the first neutron beam generating device includes atarget, a beam shaping assembly, and a collimator, the target isdisposed between the beam transmitting device and the beam shapingassembly, the charged particle beam generated by the accelerator isirradiated to the target through the beam transmitting device andinteracts with the target to generate neutrons, and the generatedneutrons sequentially pass through the beam shaping assembly and thecollimator to form the therapeutic neutron beam to be irradiated to thepatient on the treatment table.

Further, the beam shaping assembly includes a reflector, a moderator, athermal neutron absorber, a radiation shield, and a beam exit, themoderator slows down the neutrons generated from the target to anepithermal neutron energy range, the reflector surrounds the moderatorand guides deflected neutrons back to the moderator to increase theintensity of an epithermal neutron beam, the thermal neutron absorber isconfigured to absorb thermal neutrons to avoid overdosing in superficialnormal tissue during treatment, the radiation shield is disposed at therear of the reflector surrounding the beam exit, and is configured toshield against leaked neutrons and photons to reduce a dose to normaltissue in a non-irradiation area, the collimator is disposed at the rearof the beam exit to converge the neutron beam, and a radiation shieldingdevice is disposed between the patient and the beam exit to shieldnormal tissue of the patient from the radiation of beams from the beamexit.

Furthermore, the beam transmitting device has a vacuum tube configuredto accelerate or transmit the charged particle beam, the vacuum tubeprotrudes into the beam shaping assembly in the direction of the chargedparticle beam and sequentially passes through the reflector and themoderator, and the target is disposed in the moderator and is located atan end of the vacuum tube.

More particularly, the beam transmitting device includes a firsttransmitting device connected to the accelerator, a beam directionconversion device configured to convert a traveling direction of thecharged particle beam, and a second transmitting device configured totransmit the charged particle beam to the first neutron beam generatingdevice, the second transmitting device passes through the firstshielding assembly to reach the first neutron beam generating device,and the first shielding assembly covers an end, facing the accelerator,of the first neutron beam generating device and is in contact with thefirst partition wall around the first neutron beam generating device.

Further, the charged particle beam generation room includes anaccelerator room and a beam transmission room, the first transmittingdevice extends from the accelerator room to the beam transmission roomand passes through a second partition wall that separates theaccelerator room from the beam transmission room, a second shieldingassembly is disposed at a position where the first transmitting devicepasses on a side, facing the upstream of the beam transmissiondirection, of the second partition wall, the first transmitting devicepasses through the second shielding assembly and the second partitionwall, and the second shielding assembly is in contact with the secondpartition wall around the first transmitting device. The secondshielding assembly is disposed, so that neutrons that overflow or arereflected from the first transmitting device may be prevented fromentering the accelerator room.

Furthermore, the neutron capture therapy system further includes asecond irradiation room and a second neutron beam generating device thatis located in the second irradiation room, the beam transmitting deviceincludes a third transmitting device configured to transmit the chargedparticle beam to the second neutron beam generating device, the thirdtransmitting device extends from the beam transmission room to thesecond irradiation room and passes through a third partition wall thatseparates the beam transmission room from the second irradiation room, athird shielding assembly is disposed at a position where the thirdtransmitting device passes on a side, facing the upstream of the beamtransmission direction, of the third partition wall, the thirdtransmitting device passes through the third shielding assembly and thethird partition wall to reach the second neutron beam generating device,and the third shielding assembly is in contact with the third partitionwall around the third transmitting device. The third shielding assemblyis disposed, so that neutrons that overflow or are reflected from thesecond irradiation room may be prevented from entering the beamtransmission room.

Furthermore, transmission directions of the first transmitting deviceand the second transmitting device are on an XY plane, the thirdtransmitting device transmits the charged particle beam in a Z-axisdirection, and the third partition wall is the floor of the beamtransmission room or the second irradiation room.

Furthermore, the beam direction conversion device includes a first beamdirection conversion assembly and a second beam direction conversionassembly, the neutron capture therapy system further includes a thirdirradiation room and the third neutron beam generating device that is atleast partially buried in a fourth partition wall that separates thethird irradiation room from the charged particle beam generation room,the beam transmitting device includes a fourth transmitting deviceconfigured to transmit the charged particle beam to the third neutronbeam generating device and a fifth transmitting device that connects thefirst beam direction conversion assembly and the second beam directionconversion assembly, the first transmitting device branches into thethird transmitting device and the fifth transmitting device in the firstbeam direction conversion assembly, the fifth transmitting devicebranches into the second transmitting device and the fourth transmittingdevice in the second beam direction conversion assembly, a fourthshielding assembly is disposed at a position where the third neutronbeam generating device passes on a side, facing the upstream of the beamtransmission direction, of the fourth partition wall, the fourthtransmitting device passes through the fourth shielding assembly toreach the third neutron beam generating device, and the fourth shieldingassembly covers an end, facing the accelerator, of the third neutronbeam generating device and is in contact with the fourth partition wallaround the third neutron beam generating device. The fourth shieldingassembly is disposed, so that neutrons that overflow or are reflectedfrom the third neutron beam generating device can be prevented fromentering the charged particle beam generation room. The firsttransmitting device and the fifth transmitting device transmit thecharged particle beam in an X-axis direction, and the transmissiondirection of the second transmitting device and a transmission directionof the fourth transmitting device are on the XY plane and form a “Y”shape with the transmission direction of the first transmitting device.In such an arrangement manner, space may be effectively utilized, aplurality of patients may be simultaneously treated, and a beamtransmission path may not be excessively extended to ensure a smallloss.

The fourth aspect of the present disclosure provides a neutron capturetherapy system, including an accelerator, a beam transmitting device,and a neutron beam generating device, wherein the accelerator isconfigured to accelerate charged particles to generate a chargedparticle beam, the beam transmitting device is configured to transmitthe charged particle beam generated by the accelerator to the neutronbeam generating device, the neutron beam generating device is configuredto generate a therapeutic neutron beam, the neutron capture therapysystem further includes an accelerator room, a beam transmission room,and an irradiation room, the accelerator room is configured toaccommodate the accelerator, the beam transmission room is configured toat least partially accommodate the beam transmitting device, a patientreceives treatment of neutron beam irradiation in the irradiation room,the beam transmitting device passes through a first partition wall thatseparates the accelerator room from the beam transmission room and/or asecond partition wall that separates the beam transmission room from theirradiation room, and shielding assemblies are disposed at positionswhere the beam transmitting device passes on sides, facing the upstreamof a beam transmission direction, of the first partition wall and/or thesecond partition wall. The shielding assemblies are disposed, so thatneutrons that overflow or are reflected from the beam transmittingdevice and/or the irradiation room may be prevented from entering theaccelerator room and/or the beam transmission room.

The fifth aspect of the present disclosure provides a neutron capturetherapy system, including an accelerator, a beam transmitting device,and a neutron beam generating device, where the accelerator isconfigured to accelerate charged particles to generate a chargedparticle beam, the beam transmitting device is configured to transmitthe charged particle beam generated by the accelerator to the neutronbeam generating device, the neutron beam generating device is configuredto generate a therapeutic neutron beam, and the beam transmitting deviceincludes a shielding assembly for preventing neutrons and otherradioactive rays from leaking from the beam transmitting device.

Implementations of this aspect may include one or more of the followingfeatures.

More particularly, the neutron capture therapy system further includes atreatment table, the neutron beam generating device includes a target, abeam shaping assembly, and a collimator, the target is disposed betweenthe beam transmitting device and the beam shaping assembly, the chargedparticle beam generated by the accelerator is irradiated to the targetthrough the beam transmitting device and interacts with the target togenerate neutrons, and the generated neutrons sequentially pass throughthe beam shaping assembly and the collimator to form the therapeuticneutron beam to be irradiated to a patient on the treatment table.

Further, the beam shaping assembly includes a reflector, a moderator, athermal neutron absorber, a radiation shield, and a beam exit, themoderator slows down the neutrons generated from the target to anepithermal neutron energy range, the reflector surrounds the moderatorand guides deflected neutrons back to the moderator to increase theintensity of an epithermal neutron beam, the thermal neutron absorber isconfigured to absorb thermal neutrons to avoid overdosing in superficialnormal tissue during treatment, the radiation shield is disposed at therear of the reflector surrounding the beam exit, and is configured toshield against leaked neutrons and photons to reduce a dose to normaltissue in a non-irradiation area, the collimator is disposed at the rearof the beam exit to converge the neutron beam, and a radiation shieldingdevice is disposed between the patient and the beam exit to shieldnormal tissue of the patient from the radiation of beams from the beamexit.

Furthermore, the beam transmitting device has a vacuum tube configuredto accelerate or transmit the charged particle beam, the vacuum tubeprotrudes into the beam shaping assembly in the direction of the chargedparticle beam and sequentially passes through the reflector and themoderator, and the target is disposed in the moderator and is located atan end of the vacuum tube.

More particularly, the beam transmitting device includes a firsttransmitting device connected to the accelerator, a beam directionconversion device configured to switch a traveling direction of thecharged particle beam, and a second transmitting device configured totransmit the charged particle beam to the neutron beam generatingdevice, and the shielding assembly is a shielding cover surrounding thebeam direction conversion device.

Further, the beam direction conversion device includes a first beamdirection conversion assembly and a second beam direction conversionassembly, the beam transmitting device further includes a thirdtransmitting device that connects the first beam direction conversionassembly and the second beam direction conversion assembly, and theshielding cover is two cover bodies that respectively surround the firstbeam direction conversion assembly and the second beam directionconversion assembly.

Furthermore, each of the first beam direction conversion assembly andthe second beam direction conversion assembly includes a deflectionelectromagnet for deflecting the charged particle beam and a switchelectromagnet for controlling the traveling direction of the chargedparticle beam, the neutron capture therapy system further includes abeam dump configured to check an output of the charged particle beambefore treatment, the first beam direction conversion assembly or thesecond beam direction conversion assembly guides the charged particlebeam to the beam dump, each of the first transmitting device, the secondtransmitting device, and the third transmitting device includes a beamadjuster for the charged particle beam, and the second transmittingdevice includes a current monitor and a charged particle beam scanner.The neutron beam generating device includes three neutron beamgenerating device, the second transmitting device includes a fourthtransmitting device, a fifth transmitting device, and a sixthtransmitting device that respectively transmit the charged particle beamto the three neutron beam generating device, the first transmittingdevice branches into the third transmitting device and the fourthtransmitting device in the first beam direction conversion assembly, andthe third transmitting device branches into the fifth transmittingdevice and the sixth transmitting device in the second beam directionconversion assembly.

Further, the neutron capture therapy system further includes a chargedparticle beam generation room and an irradiation room, the chargedparticle beam generation room accommodates the accelerator and at leastpart of the beam transmitting device, a patient receives treatment ofneutron beam irradiation in the irradiation room, and at least part ofthe neutron beam generating device is buried in a partition wall thatseparates the irradiation room from the charged particle beam generationroom.

Furthermore, the charged particle beam generation room includes anaccelerator room and a beam transmission room, the first transmittingdevice extends from the accelerator room to the beam transmission room,the second transmitting device extends from the beam transmission roomto the neutron beam generating device, and the beam direction conversiondevice and the shielding cover are accommodated in the beam transmissionroom.

By means of the neutron capture therapy system in the presentdisclosure, space may be effectively utilized, a plurality of patientsmay be simultaneously treated, and a beam transmission path may not beexcessively extended to ensure a small loss.

Further areas of applicability will become apparent from the descriptionprovided herein. It should be understood that the description andspecific examples are intended for purposes of illustration only and arenot intended to limit the scope of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate one or more embodiments of thedisclosure and together with the written description, serve to explainthe principles of the disclosure. Wherever possible, the same referencenumbers are used throughout the drawings to refer to the same or likeelements of an embodiment.

FIG. 1 is a schematic structural diagram of a neutron capture therapysystem according to an embodiment of the present disclosure.

FIG. 2 is a schematic layout diagram of a neutron capture therapy systemon an XY plane according to an embodiment of the present disclosure.

FIG. 3 is a schematic diagram of a section A-A in FIG. 2.

DETAILED DESCRIPTION OF THE DISCLOSURE

The embodiments of the present disclosure are further described indetail below with reference to the accompanying drawings, so that thoseskilled in the art can implement the technical solutions according tothe description. An XYZ coordinate system (referring to FIG. 2 and FIG.3) in which a direction of a charged particle beam P emitted by anaccelerator is used as an X-axis direction, a direction orthogonal tothe direction of the charged particle beam P emitted by the acceleratoris used as a Y-axis direction, and a direction perpendicular to theground is used as a Z-axis direction is set below, and X, Y, and Z areused in the description of position relationships between variousconstituent elements.

As shown in FIG. 1, a neutron capture therapy system in this embodimentis preferably a boron neutron capture therapy system 100. The boronneutron capture therapy system 100 is an apparatus using BNCT to treatcancer. In BNCT, a patient 200 injected with boron (B-10) is irradiatedwith a neutron beam N to treat cancer. After the patient 200 isadministrated or injected boron (B-10)-containing pharmaceuticals, theboron-containing pharmaceuticals selectively accumulates in the tumorcell M, and then takes advantage that the boron (B-10)-containingpharmaceuticals have high neutron capture cross section and produces ⁴Heand ⁷Li heavy charged particles through ¹⁰B(n,α)⁷Li neutron capture andnuclear fission reaction. The two charged particles, with average energyat about 2.33 MeV, are of high linear energy transfer (LET) andshort-range characteristics. LET and range of the alpha particle are 150keV/micrometer and 8 micrometers respectively while those of the heavycharged particle ⁷Li are 175 keV/micrometer and 5 micrometersrespectively, and the total range of the two particles approximatelyamounts to a cell size. Therefore, radiation damage to living organismsmay be restricted at the cells' level, only the tumor cells will bedestroyed on the premise of having no major normal tissue damage.

The boron neutron capture therapy system 100 includes an accelerator 10,a beam transmitting device 20, a neutron beam generating device 30, anda treatment table 40. The accelerator 10 accelerates charged particles(such as protons and deuterons) to generate a charged particle beam Psuch as a proton beam. The beam transmitting device 20 transmits thecharged particle beam P generated by the accelerator 10 to the neutronbeam generating device 30. The neutron beam generating device 30generates a therapeutic neutron beam N to be irradiated to the patient200 on the treatment table 40.

The neutron beam generating device 30 includes a target T, a beamshaping assembly 31, and a collimator 32. The charged particle beam Pgenerated by the accelerator 10 is irradiated to the target T by thebeam transmitting device 20 and interacts with the target T to generateneutrons, and the generated neutrons sequentially pass through the beamshaping assembly 31 and the collimator 32 to form the therapeuticneutron beam N to be irradiated to the patient 200 on the treatmenttable 40. The target T is preferably a metal target. Suitable nuclearreactions are selected according to characteristics such as desiredneutron yield and energy, available accelerated charged particle energy,and current and materialization of the metal target. The most discussedtwo nuclear reactions are ⁷Li(p,n)⁷Be and ⁹Be(p,n)⁹B and are bothendothermic reactions. Energy thresholds of the two nuclear reactionsare respectively 1.881 MeV and 2.055 MeV. Epithermal neutrons at a keVenergy level are considered ideal neutron sources for BNCT.Theoretically, if a lithium metal target is bombarded with protons withenergy slightly higher than the thresholds, neutrons relatively low inenergy can be generated, and can be used clinically without manymoderations. However, both a lithium metal (Li) target and a berylliummetal (Be) target and protons of threshold energy exhibit moderately lowreaction cross sections. To generate sufficient neutron fluxes,high-energy protons are usually chosen to trigger the nuclear reactions.An ideal target is supposed to have the characteristics of high neutronyield, a generated neutron energy distribution near an epithermalneutron energy range (see details below), moderate strong-penetrationradiation, safety, low cost, easy accessibility, high temperatureresistance, and the like. However, in reality, no nuclear reactions cansatisfy all requests. The target T well known to a person skilled in theart may be made of a metal material other than Li and Be, for example,Ta or W or an alloy thereof. The accelerator 10 may be a linearaccelerator, a cyclotron, a synchrotron, and a synchrocyclotron.

The beam shaping assembly 31 may adjust beam quality of the neutron beamN generated from the interaction between the charged particle beam P andthe target T. The collimator 32 is configured to converge the neutronbeam N to provide the neutron beam N with relatively high targetingefficiency during treatment. The beam shaping assembly 31 furtherincludes a reflector 311, a moderator 312, a thermal neutron absorber313, a radiation shield 314, and a beam exit 315. Neutrons generatedfrom the interaction between the charged particle beam P and the targetT have a very wide energy spectrum, among which epithermal neutrons meettherapeutic requirements, and the content of other types of neutrons andphotons needs to be minimized to avoid harm to an operator or a patient.Therefore, the neutrons from the target T need to pass through themoderator 312 to adjust the energy (>40 keV) of fast neutrons into anepithermal neutron energy range (0.5 eV to 40 keV) and reduce thermalneutrons (<0.5 eV) as much possible. The moderator 312 is made of amaterial having a cross section for principally acting with fastneutrons but hardly acting with epithermal neutrons. In this embodiment,the moderator 312 is made of at least one of D₂O, AlF₃, Fluental™, CaF₂,Li₂CO₃, MgF₂, and Al₂O₃. The reflector 311 surrounds the moderator 312and reflects neutrons that pass through the moderator 312, so theneutrons are scattered back to the neutron beam N to increase theutilization of neutrons. The reflector 311 is made of a material withhigh neutron reflection ability. In this embodiment, the reflector 311is made of at least one of Pb or Ni. The thermal neutron absorber 313 isdisposed at the rear of the moderator 312, and is made of a materialwith a large thermal neutron reaction cross section. In this embodiment,the thermal neutron absorber 313 is made of Li-6. The thermal neutronabsorber 313 is configured to absorb thermal neutrons that pass throughthe moderator 312 to reduce the content of thermal neutrons in theneutron beam N so as to avoid overdosing in superficial normal tissueduring treatment. The radiation shield 314 is disposed at the rear ofthe reflector surrounding the beam exit 315, and is configured to shieldagainst neutrons and photons that are leaked from a part except the beamexit 315. The material of the radiation shield 314 includes at least oneof a photon shielding material and a neutron shielding material. In thisembodiment, the material of the radiation shielding 314 includes aphoton shielding material being lead (Pb) and a neutron shieldingmaterial being polyethylene (PE). It should be understood that the beamshaping assembly 31 may further have another structure, provided that anepithermal neutron beam required for treatment can be obtained. Thecollimator 32 is disposed at the rear of the beam exit 315. Theepithermal neutron beam from the collimator 32 is irradiated to thepatient 200, and is moderated by superficial normal tissue to thermalneutrons to reach tumor cells M. It should be understood that thecollimator 32 may be alternatively omitted or replaced with anotherstructure. The neutron beam from the beam exit 315 is directlyirradiated to the patient 200. In this embodiment, a radiation shieldingdevice 50 is further disposed between the patient 200 and the beam exit315 to shield normal tissue of the patient from irradiation by the beamfrom the beam exit 315. It should be understood that the radiationshielding device 50 may not be disposed. The target T is disposedbetween the beam transmitting device 20 and the beam shaping assembly31. The beam transmitting device 20 has a vacuum tube C configured toaccelerate or transmit the charged particle beam P. In this embodiment,the vacuum tube C protrudes into the beam shaping assembly 31 in thedirection of the charged particle beam P and sequentially passes throughthe reflector 311 and the moderator 312. The target T is disposed in themoderator 312 and is located at an end of the vacuum tube C, to achieverelatively good neutron beam quality. It should be understood that thetarget may be disposed in another manner, and may also be movable withrespect to the accelerator or the beam shaping assembly, to facilitatetarget replacement or uniform interaction between the charged particlebeam and the target.

Referring to FIG. 2 and FIG. 3, the entire boron neutron capture therapysystem 100 is arranged in the space of two floors L1 and L2. The boronneutron capture therapy system 100 further includes an irradiation room101 (101A, 101B, 101C) and a charged particle beam generation room 102.The patient 200 on the treatment table 40 is treated by irradiation withthe neutron beam N in the irradiation room 101 (101A, 101B, 101C). Thecharged particle beam generation room 102 accommodates the accelerator10 and at least part of the beam transmitting device 20. The neutronbeam generating device 30 may include one neutron beam generating deviceor a plurality of neutron beam generating devices, to generate one ormore therapeutic neutron beams N. The beam transmitting device 20 mayselectively transmit the charged particle beam P to one or more neutronbeam generating devices or synchronously transmit the charged particlebeam P to the plurality of neutron beam generating devices. Each neutronbeam generating device corresponds to one irradiation room 101. In thisembodiment, there are three neutron beam generating devices, namely, aneutron beam generating device 30A, a neutron beam generating device30B, a neutron beam generating device 30C, and three irradiation rooms,namely, an irradiation room 101A, an irradiation room 101B, and anirradiation room 101C. The beam transmitting device 20 includes: a firsttransmitting device 21, connected to the accelerator 10; a first beamdirection conversion assembly 22 and a second beam direction conversionassembly 23 that are configured to convert a traveling direction of thecharged particle beam P; a second transmitting device 24, connecting thefirst beam direction conversion assembly 22 and the second beamdirection conversion assembly 23; a third transmitting device 25A, afourth transmitting device 25B, and a fifth transmitting device 25C thatare configured to respectively transmit the charged particle beam P fromthe first beam direction conversion assembly 22 or the second beamdirection conversion assembly 23 to the neutron beam generating device30A, the neutron beam generating device 30B, and the neutron beamgenerating device 30C. The generated neutron beam N is then respectivelyirradiated to patients in the irradiation room 101A, the irradiationroom 101B, and the irradiation room 101C. The third transmitting device25A connects the first beam direction conversion assembly 22 and theneutron beam generating device 30A, the fourth transmitting device 25Bconnects the second beam direction conversion assembly 23 and theneutron beam generating device 30B, and the fifth transmitting device25C connects the second beam direction conversion assembly 23 and theneutron beam generating device 30C. That is, the first transmittingdevice 21 branches into the second transmitting device 24 and the thirdtransmitting device 25A in the first beam direction conversion assembly22. The second transmitting device 24 then branches into the fourthtransmitting device 25B and the fifth transmitting device 25C in thesecond beam direction conversion assembly 23. The first transmittingdevice 21 and the second transmitting device 24 transmit in an X-axisdirection. The third transmitting device 25A transmits the chargedparticle beam in a Z-axis direction. The transmission directions of thefourth transmitting device 25B and the fifth transmitting device 25C areon an XY plane and form a “Y” shape with the transmission direction ofthe first transmitting device 21 and the second transmitting device 24.The neutron beam generating device 30A, the neutron beam generatingdevice 30B, and the neutron beam generating device 30C and thecorresponding irradiation room 101A, irradiation room 101B, andirradiation room 101C are respectively disposed along the transmissiondirections of the third transmitting device 25A, the fourth transmittingdevice 25B, and the fifth transmitting device 25C. Directions ofgenerated neutron beams N are respectively the same as the transmissiondirections of the third transmitting device 25A, the fourth transmittingdevice 25B, and the fifth transmitting device 25C, so that directions ofneutron beams generated by the neutron beam generating device 30B andthe neutron beam generating device 30C are on a same plane, and thedirection of the neutron beam generated by the neutron beam generatingdevice 30A is substantially perpendicular to the plane. In such anarrangement manner, space may be effectively utilized, a plurality ofpatients may be simultaneously treated, and a beam transmission path maynot be excessively extended to ensure a small loss. It should beunderstood that the direction of the neutron beam N generated by theneutron beam generating device 30A (30B, 30C) may be alternativelydifferent from the transmission direction of the third (fourth, fifth)transmitting device 25A (25B, 25C). The transmission directions of thefirst transmitting device 21 and the second transmitting device 24 maybe alternatively different. The second transmitting device 24 mayfurther be omitted, and only one beam direction conversion assembly isused to branch the beam into two or more transmission portions. Thetransmission directions of the fourth transmitting device 25B and thefifth transmitting device 25C form a “Y” shape with the transmissiondirection of the first transmitting device 21 or may be a variation of“Y”. For example, the transmission direction of the fourth transmittingdevice 25B or the fifth transmitting device 25C is the same as thetransmission direction of the first transmitting device 21. Thetransmission directions of the fourth transmitting device 25B and thefifth transmitting device 25C may alternatively form another shape, forexample, a “T” shape or an arrow shape, with the transmission directionof the first transmitting device 21, provided that the transmissiondirections of the fourth transmitting device 25B and the fifthtransmitting device 25C form an angle greater than 0 degrees on the XYplane. The transmission directions of the fourth transmitting device 25Band the fifth transmitting device 25C may not be limited to the XYplane. The transmission direction of the third transmitting device 25Amay alternatively be not in the Z-axis direction, provided that two ofthe transmission direction of the fourth transmitting device 25B, thetransmission direction of the fifth transmitting device 25C, and thetransmission direction of the first transmitting device 21 are on thesame plane (a first plane). The transmission direction of the firsttransmitting device 21 and the transmission direction of the thirdtransmitting device 25A are also on the same plane (a second plane), andthe first plane is different from the second plane. The thirdtransmitting device 25A, the neutron beam generating device 30A, and theirradiation room 101A may be alternatively omitted. In this case, thebeam is transmitted only on the XY plane.

Each of the first beam direction conversion assembly 22 and the secondbeam direction conversion assembly 23 includes a deflectionelectromagnet for deflecting the charged particle beam P and a switchelectromagnet for controlling the traveling direction of the chargedparticle beam P. The boron neutron capture therapy system 100 mayfurther include a beam dump (not shown) configured to check an output ofthe charged particle beam P before treatment. The first beam directionconversion assembly 22 or the second beam direction conversion assembly23 may cause the charged particle beam P to depart from a regular orbitand guide the charged particle beam to the beam dump.

The first transmitting device 21, the second transmitting device 24, thethird transmitting device 25A, the fourth transmitting device 25B, andthe fifth transmitting device 25C are all constructed by the vacuum tubeC, and may be respectively formed by connecting a plurality ofsub-transmitting devices. Transmission directions of the plurality ofsub-transmitting devices may be the same or different. For example, thedeflection electromagnet is used to deflect a beam transmissiondirection. The transmission directions of the first transmitting device21, the second transmitting device 24, the third transmitting device25A, the fourth transmitting device 25B, and the fifth transmittingdevice 25C may be respectively the transmission direction of anysub-transmitting device, where each of the formed first plane and secondplane is a plane formed by a sub-transmitting device directly connectedto the beam direction conversion assembly, and may respectively furtherinclude a beam adjuster (not shown) for the charged particle beam P. Thebeam adjuster includes a horizontal steering and a horizontal andvertical steering configured to adjust an beam axis of the chargedparticle beam P, a quadrupole electromagnet configured to suppressdivergence of the charged particle beam P, a four-direction slitconfigured to shape the charged particle beam P, and the like. Each ofthe third transmitting device 25A, the fourth transmitting device 25B,and the fifth transmitting device 25C may include a current monitor (notshown) and a charged particle beam scanner (not shown) as required. Thecurrent monitor measures a current value (that is, an amount of charge,a radiation dose rate) of the charged particle beam P with which thetarget T is irradiated in real time. The charged particle beam scannerscans the charged particle beam P and controls irradiation of the targetT with the charged particle beam P, for example, controls an irradiationposition of the target T with the charged particle beam P.

The charged particle beam generation room 102 may include an acceleratorroom 1021 and a beam transmission room 1022. The accelerator room 1021occupies two floors. The accelerator 10 extends from L2 to L1. The beamtransmission room 1022 is located on L2. The first transmitting device21 extends from the accelerator room 1021 to the beam transmission room1022. The irradiation room 101B and the irradiation room 101C arelocated on L2. The irradiation room 101A is located on L1. In thisembodiment, L1 is below L2. To be specific, the floor of L2 is theceiling of L1. It should be understood that L1 and L2 may be exchanged.The material of the floor (ceiling) S may be concrete with a thicknessgreater than 0.5 m or boron-containing barite concrete. The irradiationroom 101A, the irradiation room 101B, the irradiation room 101C, and thebeam transmission room 1022 have shielded spaces surrounded by ashielding wall W1. The shielding wall W1 may be a wall that is made ofboron-containing barite concrete and has a thickness greater than 1 mand a density of 3 g/c.c., and includes first partition shielding wallsW2 that separates the beam transmission room 1022 from the irradiationroom 101B and the irradiation room 101C, a second partition shieldingwall W3 that separates the accelerator room 1021 from the beamtransmission room 1022 on L1, and a third partition shielding wall W4that separates the accelerator room 1021 from the irradiation room 101Aon L2. The accelerator room 1021 is surrounded by a concrete wall W, thesecond partition shielding wall W3, and the third partition shieldingwall W4 with a thickness greater than 1 m. At least part of the neutronbeam generating device 30B and at least part of the neutron beamgenerating device 30C are buried in the first partition shielding wallW2. The fourth transmitting device 25B and the fifth transmitting device25C respectively extend from the beam transmission room 1022 to theneutron beam generating device 30B and the neutron beam generatingdevice 30C. The neutron beam generating device 30A is located in theirradiation room 101A, and the third transmitting device 25A extendsfrom the beam transmission room 1022 to the irradiation room 101Athrough the floor S. The irradiation room 101A, the irradiation room101B, and the irradiation room 101C respectively have shielding doorsD1, D2, D3 for the treatment table 40 and doctors to pass. Theaccelerator room 1021 respectively has a shielding door D4 and ashielding door D5 on L1 and L2 for access to the accelerator room 1021to maintain the accelerator 10. The beam transmission room 1022 has ashielding door D6 for access from the accelerator room 1021 to the beamtransmission room 1022 to maintain the beam transmitting device 20. Theshielding door D6 is disposed on the second partition shielding wall W3.Inner shielding walls W5 are further provided in the irradiation room101A, the irradiation room 101B, and the irradiation room 101C to formlabyrinth passages from the shielding door D1, the shielding door D2,and the shielding door D3 to beam exits, which may prevent directirradiation of radioactive rays when the shielding door D1, theshielding door D2, and the shielding door D3 are open by accident.According to different layouts in irradiation rooms, the inner shieldingwalls W5 may be disposed at different positions. A shielding door D7inside the irradiation room may further be disposed between the innershielding wall W5 and the shielding wall W1 or the third partitionshielding wall W4 to form secondary protection during treatment withneutron beam irradiation. The inner shielding wall W5 may be a wall thatis made of a boron-containing barite concrete and has a thicknessgreater than 0.5 m and a density of 3 g/c.c. Each of the shielding doorD1, the shielding door D2, the shielding door D3, the shielding door D4,the inner shielding door D5, the shielding door D6, and the shieldingdoor D7 may include a primary shielding door D and a secondary shieldingdoor D′ that are independent of each other or may include only a primaryshielding door D or a secondary shielding door D′, which may bedetermined based on an actual case. The primary shielding door D may bemade of the same material, for example, boron-containing PE or bariteconcrete or lead having a thickness greater than 0.5 m and a density of6 g/c.c. The secondary shielding door D′ may be made of the samematerial, for example, boron-containing PE or barite concrete or leadhaving a thickness greater than 0.2 m and a density of 6 g/c.c. In thisembodiment, each of the shielding door D1, the shielding door D4, theshielding door D5, and the shielding door D6 includes the primaryshielding door D and the secondary shielding door D′, each of theshielding door D1, the shielding door D2, and the shielding door D3includes only the primary shielding door D, and the shielding door D7includes only the secondary shielding door D′. A shielding wall and ashielding door form a shielding space to suppress phenomena thatradioactive rays enter the irradiation room 101A, the irradiation room101B, the irradiation room 101C, and the beam transmission room 1022from outside and leave these rooms. In this embodiment, the secondpartition shielding wall W3 that separates the accelerator room 1021from the beam transmission room 1022 is disposed between the accelerator10 and the first beam direction conversion assembly 22. That is, thefirst transmitting device 21 passes through the second partitionshielding wall W3. It should be understood that the second partitionshielding wall W3 and the shielding door D6 may be omitted or may bealternatively disposed at another position, for example, between thefirst beam direction conversion assembly 22 and the second beamdirection conversion assembly 23 or between the second beam directionconversion assembly 23 and the neutron beam generating device 30B andthe neutron beam generating device 30C. Alternatively, an additionalpartition shielding wall and shielding door is disposed between thesecond partition shielding wall W3 and the first partition shieldingwall W2. That is, a shielding wall is disposed between the neutron beamgenerating device and the accelerator. During repair and maintenance ofthe accelerator, an operator is protected from irradiation by neutronsand other radioactive rays leaked from the neutron beam generatingdevice, and the same time reactions in which the accelerator isactivated by neutrons are reduced.

Neutrons and other radioactive rays tend to leak at a position where anassembly or element passing through a shielding wall or floor. Forexample, in this embodiment, the neutron beam generating device 30B andthe neutron beam generating device 30C pass through the first partitionshielding wall W2, the first transmitting device 21 passes through thesecond partition shielding wall W3, and the third transmitting device25A passes through the floor S. A first shielding assembly 60, a secondshielding assembly 70, and a third shielding assembly 80 may berespectively disposed at positions where the neutron beam generatingdevice 30B, the neutron beam generating device 30C, the firsttransmitting device 21, and the third transmitting device 25A pass onsides, facing the upstream of the beam transmission direction, of thefirst partition shielding wall W2, the second partition shielding wallW3, and the floor S. The first shielding assembly 60 covers ends, facingthe accelerator, of the neutron beam generating device 30B and theneutron beam generating device 30C and is in contact with the firstpartition shielding walls W2 around the neutron beam generating device30B and the neutron beam generating device 30C, so that neutrons thatoverflow or are reflected from the beam shaping assemblies of theneutron beam generating device 30B and the neutron beam generatingdevice 30C are prevented from entering the accelerator room 1021 and thebeam transmission room 1022. The fourth transmitting device 25B and thefifth transmitting device 25C pass through the first shielding assembly60 to reach the targets T of the neutron beam generating device 30B andthe neutron beam generating device 30C. The second shielding assembly 70is in contact with the second partition shielding wall W3 around thefirst transmitting device 21, so that neutrons that overflow or arereflected from the beam transmitting device 20 are prevented fromentering the accelerator room 1021. The first transmitting device 21passes through the second shielding assembly 70 and the second partitionshielding wall W3 to reach the first beam direction conversion assembly22. The third shielding assembly 80 is in contact with the floor Saround the third transmitting device 25A, so that neutrons that overflowor are reflected from the irradiation room 101A are prevented fromentering the beam transmission room 1022. The third transmitting device25A passes through the third shielding assembly 80 and the floor S toreach the neutron beam generating device 30A. The materials of the firstshielding assembly 60, the second shielding assembly 70, and the thirdshielding assembly 80 may be boron-containing PE or barite concrete orlead.

The first beam direction conversion assembly 22 and the second beamdirection conversion assembly 23 are respectively surrounded by ashielding cover 26 to prevent neutrons and other radioactive rays fromleaking from the beam direction conversion assembly. The material of theshielding cover 26 may be boron-containing PE or barite concrete orlead. It should be understood that the first beam direction conversionassembly 22 and the second beam direction conversion assembly 23 may bealternatively surrounded together by one shielding cover 26. Theremaining other parts such as the vacuum tubes of the beam transmittingdevice may be alternatively surrounded by the shielding cover, therebypreventing neutrons and other radioactive rays from leaking from thebeam transmitting device.

The boron neutron capture therapy system 100 may further include apreparation room, a control room, and another space used to assist intreatment. Each irradiation room may be provided with one preparationroom used for preparation work, for example, securing a patient to atreatment table, injecting boron-containing pharmaceuticals, andsimulating a treatment plan before treatment with irradiation. Aconnecting passage is disposed between the preparation room and theirradiation room. After the preparation work is completed, the patientis directly pushed into the irradiation room or a control mechanismcontrols automatic entry of the patient into the irradiation room by arail. The preparation room and the connecting passage may also be closedby a shielding wall. The preparation room further has a shielding door.The control room is configured to control the accelerator, the beamtransmitting device, the treatment table, and the like, and control andmanage the entire irradiation process. A manager may furthersimultaneously monitor a plurality of the irradiation rooms in thecontrol room.

It should be understood that, in this embodiment, the shielding walls(including concrete walls W), the shielding door, the shieldingassembly, and the shielding cover may all have other thicknesses ordensities or may be replaced with other materials.

Although the illustrative embodiments of the present invention have beendescribed above in order to enable those skilled in the art tounderstand the present invention, it should be understood that thepresent invention is not to be limited the scope of the embodiments. Forthose skilled in the art, as long as various changes are within thespirit and scope as defined in the present invention and the appendedclaims, these changes are obvious and within the scope of protectionclaimed by the present invention.

What is claimed is:
 1. A neutron capture therapy system, comprising: anaccelerator configured to accelerate charged particles to generate acharged particle beam; a beam transmitting device configured to transmitthe charged particle beam generated by the accelerator, wherein the beamtransmitting device comprises a first transmitting device connected tothe accelerator, a beam direction conversion device configured toconvert a traveling direction of the charged particle beam, a secondtransmitting device, a third transmitting device, and a fourthtransmitting device; and a neutron beam generating device configured togenerate a therapeutic neutron beam, wherein the charged particle beamis transmitted to the neutron beam generating device through the beamtransmitting device, and the neutron beam generating device comprises afirst neutron beam generating device, a second neutron beam generatingdevice, and a third neutron beam generating device; wherein the secondtransmitting device, the third transmitting device and the fourthtransmitting device respectively transmit the charged particle beam fromthe beam direction conversion device to the first neutron beamgenerating device, the second neutron beam generating device, and thethird neutron beam generating device, and wherein two of the firsttransmitting device, the third transmitting device, and the fourthtransmitting device define a first plane, the first transmitting deviceand the second transmitting device define a second plane, and the firstplane is different from the second plane.
 2. The neutron capture therapysystem according to claim 1, wherein the first transmitting devicetransmits the charged particle beam in an X-axis direction, andtransmission directions of the third transmitting device and the fourthtransmitting device are on an XY plane and form an angle greater than 0degrees.
 3. The neutron capture therapy system according to claim 2,wherein the second transmitting device transmits the charged particlebeam in a Z-axis direction, and the transmission directions of the thirdtransmitting device and the fourth transmitting device and atransmission direction of the first transmitting device form a “Y”shape.
 4. The neutron capture therapy system according to claim 1,wherein the first neutron beam generating device, the second neutronbeam generating device, and the third neutron beam generating device arerespectively disposed along transmission directions of the secondtransmitting device, the third transmitting device, and the fourthtransmitting device, directions of neutron beams generated by the firstneutron beam generating device, the second neutron beam generatingdevice, and the third neutron beam generating device are respectivelysame as the transmission directions of the second transmitting device,the third transmitting device, and the fourth transmitting device, sothat the directions of the neutron beams generated by the second neutronbeam generating device and the third neutron beam generating device areon a same plane, and the direction of the neutron beam generated by thefirst neutron beam generating device is substantially perpendicular tothe plane.
 5. The neutron capture therapy system according to claim 1,further comprising a beam dump configured to check an output of thecharged particle beam before treatment, wherein the beam directionconversion device comprises a first beam direction conversion assemblyand a second beam direction conversion assembly, the beam transmittingdevice further comprises a fifth transmitting device that connects thefirst beam direction conversion assembly and the second beam directionconversion assembly, the second transmitting device connects the firstbeam direction conversion assembly and the first neutron beam generatingdevice, the third transmitting device connects the second beam directionconversion assembly and the second neutron beam generating device, andthe fourth transmitting device connects the second beam directionconversion assembly and the third neutron beam generating device, eachof the first beam direction conversion assembly and the second beamdirection conversion assembly comprises a deflection electromagnetconfigured to deflect the charged particle beam and a switchelectromagnet configured to control the traveling direction of thecharged particle beam, the first beam direction conversion assembly orthe second beam direction conversion assembly guides the chargedparticle beam to the beam dump, each of the first transmitting device,the second transmitting device, the third transmitting device, thefourth transmitting device, and the fifth transmitting device comprisesa beam adjuster for the charged particle beam, and each of the secondtransmitting device, the third transmitting device, and the fourthtransmitting device comprises a current monitor and a charged particlebeam scanner.
 6. The neutron capture therapy system according to claim1, further comprising an irradiation room, wherein a patient receivestreatment of neutron beam irradiation in the irradiation room, theirradiation room comprises a first irradiation room, a secondirradiation room, and a third irradiation room that respectivelycorrespond to the first neutron beam generating device, the secondneutron beam generating device, and the third neutron beam generatingdevice, and the first irradiation room, the second irradiation room, andthe third irradiation room are respectively disposed along transmissiondirections of the second transmitting device, the third transmittingdevice, and the fourth transmitting device.
 7. The neutron capturetherapy system according to claim 6, wherein further comprising acharged particle beam generation room, wherein the charged particle beamgeneration room accommodates the accelerator and at least part of thebeam transmitting device and comprises an accelerator room and a beamtransmission room, the first transmitting device extends from theaccelerator room to the beam transmission room, at least part of thesecond neutron beam generating device and at least part of the thirdneutron beam generating device are respectively buried in partitionwalls that respectively separate the second irradiation room and thethird irradiation room from the beam transmission room, the thirdtransmitting device and the fourth transmitting device respectivelyextend from the beam transmission room to the second neutron beamgenerating device and the third neutron beam generating device, thefirst neutron beam generating device is located in the first irradiationroom, the second transmitting device extends from the beam transmissionroom to the first irradiation room through the floor, and the neutroncapture therapy system further comprises a preparation room and acontrol room.
 8. A neutron capture therapy system comprising: anaccelerator configured to accelerate charged particles to generate acharged particle beam; a beam transmitting device configured to transmitthe charged particle beam generated by the accelerator; a first neutronbeam generating device configured to generate a therapeutic neutronbeam, wherein the charged particle beam is transmitted to the firstneutron beam generating device through the beam transmitting device; anda first shielding wall disposed between the first neutron beamgenerating device and the accelerator to protect an operator fromirradiation by neutrons and other radioactive rays leaked from the firstneutron beam generating device during repair and maintenance of theaccelerator and reduce reactions in which the accelerator is activated.9. The neutron capture therapy system according to claim 8, furthercomprising a charged particle beam generation room and a firstirradiation room, wherein the charged particle beam generation roomaccommodates the accelerator and at least part of the beam transmittingdevice, a patient receives treatment of neutron beam irradiation in thefirst irradiation room, at least part of the first neutron beamgenerating device is buried in a first partition wall that separates thefirst irradiation room from the charged particle beam generation room,and the first shielding wall is disposed in the charged particle beamgeneration room.
 10. The neutron capture therapy system according toclaim 9, wherein the charged particle beam generation room comprises anaccelerator room and a beam transmission room, the beam transmittingdevice comprises a first transmitting device that is connected to theaccelerator and extends from the accelerator room to the beamtransmission room and a second transmitting device that extends from thebeam transmission room to the first neutron beam generating device andtransmits the charged particle beam to the first neutron beam generatingdevice, the first partition wall is a partition wall that separates thefirst irradiation room from the beam transmission room, the firstshielding wall is a partition wall between the accelerator room and thebeam transmission room, and the first transmitting device passes throughthe first shielding wall.
 11. The neutron capture therapy systemaccording to claim 10, wherein the first transmitting device comprises afirst beam direction conversion assembly and a second beam directionconversion assembly configured to switch a traveling direction of thecharged particle beam, a third transmitting device that connects theaccelerator and the first beam direction conversion assembly, a fourthtransmitting device that connects the first beam direction conversionassembly and the second beam direction conversion assembly, and a fifthtransmitting device that connects the second transmitting device and thesecond beam direction conversion assembly, the first shielding wall isdisposed between the accelerator and the first beam direction conversionassembly, and the third transmitting device passes through the firstshielding wall; or the first shielding wall is disposed between thesecond beam direction conversion assembly and the first neutron beamgenerating device, and the fifth transmitting device passes through thefirst shielding wall; or the first shielding wall is disposed betweenthe first beam direction conversion assembly and the second beamdirection conversion assembly, and the fourth transmitting device passesthrough the first shielding wall.
 12. The neutron capture therapy systemaccording to claim 11, further comprising a second neutron beamgenerating device and a second irradiation room, wherein at least partof the second neutron beam generating device is buried in a secondpartition wall that separates the second irradiation room from the beamtransmission room, the beam transmitting device further comprises asixth transmitting device that extends from the beam transmission roomto the second neutron beam generating device and transmits the chargedparticle beam to the second neutron beam generating device, the firsttransmitting device further comprises a seventh transmitting device thatconnects the sixth transmitting device and the second beam directionconversion assembly, when the first shielding wall is disposed betweenthe second beam direction conversion assembly and the first neutron beamgenerating device, the seventh transmitting device also passes throughthe first shielding wall, each of the first beam direction conversionassembly and the second beam direction conversion assembly comprises adeflection electromagnet for deflecting the charged particle beam and aswitch electromagnet for controlling the traveling direction of thecharged particle beam, the neutron capture therapy system furthercomprises a beam dump configured to check an output of the chargedparticle beam before treatment, the first beam direction conversionassembly or the second beam direction conversion assembly guides thecharged particle beam to the beam dump, each of the first transmittingdevice, the second transmitting device, and the sixth transmittingdevice comprises a beam adjuster for the charged particle beam, and eachof the second transmitting device and the sixth transmitting devicecomprises a current monitor and a charged particle beam scanner.
 13. Theneutron capture therapy system according to claim 9, wherein a secondshielding wall is disposed between the first partition wall and thefirst shielding wall.
 14. The neutron capture therapy system accordingto claim 8, wherein a shielding door is disposed in the first shieldingwall, and the shielding door comprises a primary shielding door and asecondary shielding door or only comprises a primary shielding door orsecondary shielding door.
 15. A neutron capture therapy systemcomprising: an accelerator configured to accelerate charged particles togenerate a charged particle beam; a beam transmitting device configuredto transmit the charged particle beam generated by the accelerator,wherein the beam transmitting device further comprises a shieldingassembly for preventing neutrons and other radioactive rays from leakingfrom the beam transmitting device; and a neutron beam generating deviceconfigured to generate a therapeutic neutron beam, wherein the chargedparticle beam is transmitted to the neutron beam generating devicethrough the beam transmitting device.
 16. The neutron capture therapysystem according to claim 15, wherein the beam transmitting devicecomprises a first transmitting device connected to the accelerator, abeam direction conversion device configured to switch a travelingdirection of the charged particle beam, and a second transmitting deviceconfigured to transmit the charged particle beam to the neutron beamgenerating device, and the shielding assembly is a shielding coversurrounding the beam direction conversion device.
 17. The neutroncapture therapy system according to claim 16, further comprising the abeam dump configured to check an output of the charged particle beambefore treatment, wherein the beam direction conversion device comprisesa first beam direction conversion assembly and a second beam directionconversion assembly, the beam transmitting device further comprises athird transmitting device that connects the first beam directionconversion assembly and the second beam direction conversion assembly,and the shielding cover is two cover bodies that respectively surroundthe first beam direction conversion assembly and the second beamdirection conversion assembly, each of the first beam directionconversion assembly and the second beam direction conversion assemblycomprises a deflection electromagnet for deflecting the charged particlebeam and a switch electromagnet for controlling the traveling directionof the charged particle beam, the first beam direction conversionassembly or the second beam direction conversion assembly guides thecharged particle beam to the beam dump, each of the first transmittingdevice, the second transmitting device, and the third transmittingdevice comprises a beam adjuster for the charged particle beam, and thesecond transmitting device comprises a current monitor and a chargedparticle beam scanner.
 18. The neutron capture therapy system accordingto claim 17, wherein the neutron beam generating device comprises threeneutron beam generating device, the second transmitting device comprisesa fourth transmitting device, a fifth transmitting device, and a sixthtransmitting device that respectively transmit the charged particle beamto the three neutron beam generating device, the first transmittingdevice branches into the third transmitting device and the fourthtransmitting device in the first beam direction conversion assembly, andthe third transmitting device branches into the fifth transmittingdevice and the sixth transmitting device in the second beam directionconversion assembly.
 19. The neutron capture therapy system according toclaim 16, further comprising a charged particle beam generation room andan irradiation room, wherein the charged particle beam generation roomaccommodates the accelerator and at least part of the beam transmittingdevice, a patient receives treatment of neutron beam irradiation in theirradiation room, and at least part of the neutron beam generatingdevice is buried in a partition wall that separates the irradiation roomfrom the charged particle beam generation room.
 20. The neutron capturetherapy system according to claim 19, wherein the charged particle beamgeneration room comprises an accelerator room and a beam transmissionroom, the first transmitting device extends from the accelerator room tothe beam transmission room, the second transmitting device extends fromthe beam transmission room to the neutron beam generating device, andthe beam direction conversion device and the shielding cover areaccommodated in the beam transmission room.